<%@page contentType="text/html;charset=UTF-8" import="
    javax.jcr.Node,
    javax.jcr.NodeIterator,
    javax.jcr.Session"
%><%@taglib prefix="sling" uri="http://sling.apache.org/taglibs/sling/1.0"%><%
%><sling:defineObjects/><%!
    
    final String propertyName  = "sling:resourceType";
    final String propertyValue = "movies/components/movie";
    
%><%

    final Session jcrSession = currentNode.getSession();
    
    NodeIterator children = currentNode.getNodes();
    while (children.hasNext()) {
        Node child = children.nextNode();
        child.setProperty(propertyName, propertyValue);
    }
    
    jcrSession.save();

%>

Done.
